Text messages have been popular among users of portable devices, such as a cell phone and a smart phone. Lately, the user of text message increases abruptly while the use of voice calls decreases. The research organization Nielsen reported in 2010 that the total call volume of a mobile phone subscriber was reduced to about 700 minutes per month. Furthermore, a research of the trade association CTIA shows that the average duration of a wireless call has been reduced from about 3 minutes to about 1 minute and 40 seconds since the mid-2007.
Unlike the voice calls, the number of messages used per a month among mobile phone subscribers increases to about 700 messages, according to the Nielsen. This might be resulted from restless thumbs of teenagers. They generally own smart phones, substantially a computer in their hands, and frequently send messages through social networks. Recently, the world's largest social network Facebook stated that a third of 60 million subscribers use Facebook services through their smart phones. As described, a user of a mobile terminal may transmit and receive a large number of messages for communication with other parties in daily life. Since a user exchanges so many messages with multiple parties daily, there is a need for an efficient method of managing messages through a related terminal.